This invention relates generally to popcorn poppers and more specifically to an automatic popcorn popper which produces popcorn in consecutive batches while reducing the amount of attention required from an operator. This invention also relates to an improved method for popping popcorn.
Popcorn is mass-produced for sale at movies and other events in commercial popcorn poppers which include an enclosed, transparent cabinet containing a tiltable kettle suspended above a catch area or platform. The kettle is heated and uncooked popcorn kernels are placed therein to be cooked and popped. Once the kernels are popped, the kettle is manually tilted and the popcorn spills onto the platform to be scooped up, packaged and sold to customers.
Conventionally, commercial popcorn poppers have been manually operated and have required an operator""s constant attention for cooking the kernels and subsequently dumping the popped popcorn. For example, an operator would load the kettle with popping oil and unpopped corn kernels and then listen and watch for the unpopped corn to pop. When the operator decided, somewhat arbitrarily, that the corn was sufficiently popped, they would then dump the kettle and spill the popcorn onto the serving platform. Additional oil and corn would then be added for the next batch. While such conventional popcorn poppers are generally effective in mass-producing popcorn; the constant attention they require prevents the operator from other important tasks, such as selling the popcorn and other concession products, taking money and generally servicing customers.
As may be appreciated, the multiple duties entrusted concessionaire operators are not conducive to having them constantly monitor a popcorn popper. If attention is diverted for an extended length of time, the popcorn is susceptible to being burned or overcooked. In addition to the waste of burned popcorn, the aroma of the burned popcorn is not attractive to customers and may actually discourage purchases. Furthermore, if the operator inadvertently dumps the burned corn onto the platform, it will contaminate the usable popcorn which has already been produced and may render the entire batch inedible and thus unusable. Still further, the results and mess from burned popcorn is not easy to clean. The kettle is hot and must be allowed to cool before the burned popcorn is removed and the kettle placed back in service.
Additionally, the arbitrary nature of the dumping process with conventional poppers makes them subject to messes associated with premature dumping. For example, if the operator mistakenly believes that the corn has been completely popped and the oil used when indeed uncooked corn and oil remains in the kettle, tilting the kettle will spill oil onto the serving platform and possibly onto the counter. Such spills ruin and waste popcorn and create a mess which must be cleaned, adding to the already numerous tasks of a concessionaire.
Still further, too much oil may be added for a particular cooking cycle, and even if the cooking cycle is completed, excess oil might be left, again resulting in a mess upon dumping of the batch. For example, one operator may load the uncooked corn and oil for a batch, and another operator may subsequently and inadvertently load more oil, believing it had not been added. The excess oil does not burn off or cook and remains in the kettle. Not only is a mess created upon dumping, but the excess oil may also foul the batch of popcorn.
Another drawback of conventional popcorn poppers is the inherent delays which will occur between cooked batches of popcorn. When the popcorn has been cooked and dumped, the operator may begin serving it to customers without replenishing the supply of corn and oil and starting the next batch. Therefore, the next batch of popcorn will not be produced until the operator consciously sets aside time from his other activities to do so. Such delays interrupt production rates and introduce inefficiencies into the operation which reduce popcorn sales.
It is also desirable to pop popcorn consistently so that it produces consistent taste from batch to batch. The vagaries of prior systems leave much to chance in this regard so that batches of corn are undercooked, burned or the like and at the least are inconsistent in taste.
Still another drawback to conventional popping mechanisms is that they sometimes provide inconsistent or improper heating of the popcorn so that proper expansion of the kernels upon popping is not achieved. Particularly, when the heat is too high, the steam from the kernel is prematurely forced out and the popped kernel is small. If the temperature is too low, the kernels do not experience proper hull expansion and brittleness at popping and the popped kernels are small. As may be appreciated, small popcorn kernels reduce the yield of popped popcorn per unit of uncooked kernels, thus reducing the efficiently of the popping apparatus and raising the cost of the operation.
As a result, it is one objective of the present invention to provide improved apparatus and/or methods to pop popcorn continuously in consecutive batches with minimal attention by an operator.
It is another objective to ensure that the popcorn is consistently and properly cooked in each batch.
It is a further objective of the present invention to reduce the burning of popcorn sometimes associated with conventional machines and operator inattention.
It is also an objective of the invention to always provide the proper amount of cooking oil and thus reduce the messes associated with such burned popcorn or spilled, uncooked oil and thereby allow an operator to focus upon customers and popcorn sales.
It is a still further objective of the invention to reduce the delays between fresh batches of popcorn attributable to lack of attention by the operator.
It is a still further objective of the invention to increase the production rate of consecutive batches of fresh popcorn to thereby increase the sales from and the profitability of a commercial popcorn popper.
Still further, it is an objective to provide the proper and consistent temperature to the kernels as they cook to ensure proper popping conditions and to maximize the popcorn yield per unit of kernels.
Addressing these objectives, the present invention comprises a popcorn popper which may be left unattended to automatically cook and dump popcorn once it has been loaded with the proper ingredients, such as uncooked popcorn. The proper, premeasured amount of oil pump is then added by the oil pump system upon the initiation of a cooking cycle so that the operator does not have to worry about measuring oil or excess oil in the kettle. The popcorn popper of the invention is responsive to kettle temperature conditions to automatically cook popcorn kernels, subsequently dump the finished popcorn, and then alert the operator to load more ingredients such as oil and uncooked kernels, and start the next batch. In that way, all of the batches of fresh popcorn are properly cooked at regular periods with the proper amount of oil and heat, and the operator is left to attend to other tasks.
According to the invention, popcorn is consistently cooked by introducing an amount of popcorn and oil to a cooking system, comprising a heated kettle, for a duration sufficient to heat the corn and oil a predetermined amount, and then automatically dumping popped popcorn after a sufficient amount of heat energy has been absorbed by the corn and the oil to pop the corn. The application of heat energy to the corn and oil is not monitored and controlled by time, but rather by the heat conditions of the cooking system for each batch. In this regard, a kettle is heated to a start temperature and cycled about that temperature through a small temperature range. When unpopped corn and oil are introduced, a thermocouple on the kettle senses a temperature drop (cycle point) and a cooking or popping cycle begins. The corn and oil absorb the heat energy and are heated in the kettle until the kettle temperature climbs back to a predetermined temperature (dump point) indicating sufficient heat energy has been applied to the corn and oil to pop the corn. At that point, the kettle is automatically dumped.
Since the controller is temperature, rather then time responsive, the operator is assured a consistent amount of heat is always applied to the corn and oil for consistent popping. If the kettle dump was controlled by time alone, and the environment changed, such as a cabinet door being open, the cooking cycle might time out before sufficient heat energy was applied to consistently cook that batch of corn. Moreover, since the start temperature is held within a narrow predetermined range, the oil and corn will not be prematurely burned and the temperature gradients applied thereto will be more consistent. Also, such a method accommodates at least some variations in the amount of corn and oil introduced to the kettle. If too little, the temperature drop will not be as great and the rise to the predetermined dump temperatures takes a shorter time, thus sufficient but less heat is introduced so this batch is consistently popped. In a corresponding manner, larger amounts of corn and oil will slow the climb of temperature to the dump point insuring that sufficient heat is imparted to pop the corn consistently with other batches.
To further ensure proper cooking by the invention, a premeasured amount of oil is introduced to the kettle at the beginning of a cooking cycle. The controller is coupled to an oil pump system which is operably in fluid communication with the kettle. Upon the kettle reaching the proper start temperature or cooking temperature, the oil pump system and an oil pump switch are enabled. The operator then actuates the oil pump switch to activate the pump system and deliver a proper, premeasured amount of oil to the kettle. The oil pump system and switch are disabled by the controller if the kettle heat is not ON (no cooking cycle) or the kettle is tilted from an upright position, such as to be cleaned. Furthermore, in accordance with the principles of the present invention, the oil pump system will only deliver one load of oil per cooking cycle to prevent an oil overload or spilling of oil when the cooked batch of popcorn is dumped. Therefore, the oil pump switch may be actuated numerous times and only one load of oil will be delivered per cooking cycle.
In an alternative embodiment of the invention, the controller is operable to activate the oil pump system automatically upon the initiation of a cooking cycle. To that end, the controller provides an output signal to the oil pump system to pump a premeasured amount of oil to the kettle at a predetermined time in the cooking cycle. For example, the oil might be added when the kettle has risen to a start temperature or might be added after the popcorn has been added. If the oil pump system has a mechanically adjusted timer mechanism for pumping a premeasured amount, an output signal is provided by the controller to activate the pump and pump oil into the kettle. If the oil pump system includes a programmable timer mechanism, the controller is operable to provide additional timer outputs to adjust the amount of time that the pump will deliver oil when activated. In either case, a premeasured and proper amount of oil is delivered to the kettle each cooking cycle. The controller will not activate the pump system until the kettle is hot and ready to cook and is upright.
More specifically, the popper apparatus includes a kettle which is coupled to a dumping motor and a heater which are controlled by a controller which monitors the kettle temperature. The controller includes a temperature sensor, such as a thermocouple, which is operably connected to the kettle proximate the heaters. By monitoring the temperature of the kettle, the controller is operable to dump the kettle at the proper time and to alert the operator when another batch of uncooked corn kernels should be added to the kettle. Since the kettle temperature is constantly monitored, and the dump cycle is automatically controlled, the burning of popcorn is prevented. Furthermore, an operator does not have to constantly monitor the procedure to prevent such burning and can thus turn his attention to other tasks. The popper begins a cooking or popping cycle when fresh ingredients are added, and by alerting the operator at the end of each popping cycle, the popper effectively reduces the delay between batches to increase its productivity.
In a preferred embodiment of the invention, a programmable logic controller (PLC) is coupled to a temperature controller which, in turn, is coupled to a kettle thermocouple and to kettle heaters. When the popper is turned ON and the kettle heat is turned ON, the kettle is heated to an equilibrium start or cooking temperature of, for example, approximately 525xc2x0 F. The thermocouple and temperature controller preferably maintain the desired 525xc2x0 F. kettle cooking temperature in a small cycled range of +/xe2x88x9210xc2x0 F. When the kettle has reached the equilibrium start temperature, the PLC activates indicators which provide visual and audible indications that the kettle is ready to make popcorn. The oil pump system and pump switch are enabled and the operator actuates the oil pump switch to load the oil which is pumped in by the oil pump, and also loads the uncooked popcorn kernels.
Alternatively, the oil might be loaded by hand by the operator. In still another alternative embodiment of the invention, as discussed above, the PLC provides outputs directly to the oil pump system to automatically pump oil to the kettle at the initiation of a cooking cycle. The PLC is operably coupled to the oil pump system to activate the pump for a predetermined amount of time to ensure a premeasured amount of oil. A timer determines how long the pump runs once activated to ensure the proper amount of oil. The invention may incorporate an oil pump system having a mechanically adjusted timer, such as a dial timer, or may incorporate a system having a separate programmable timer. In the latter case, the PLC is operable to provide separate output signals to the programmable timer to set the pump time in addition to any output signals to the pump for delivering oil for the amount of time set by the timer.
The temperature controller senses the rapid drop in kettle temperature associated with the absorption of heat from the kettle by the corn and oil. When the temperature drop exceeds a set amount, for example, 50xc2x0 F. below the equilibrium start temperature, the PLC initiates a cooking cycle. The point of initiation of the cooking cycle is designated the cycle temperature or cycle point.
As the cooking cycle progresses, the PLC senses through the temperature controller, that the kettle has dropped to a minimum temperature below the cycle temperature. The minimum temperature will depend upon the heat load added to the kettle. As the popcorn pops, the temperature of the kettle begins to rise above the minimum temperature. When the kettle temperature reaches a predetermined dump temperature or dump point and the PLC that the minimum temperature was previously reached and was preceded by the cycle temperature, the popper indicates that the end of the cooking cycle has occurred. Preferably, the predetermined kettle dump temperature associated with the dump point for determining the end of a cooking cycle is equal to the cycle temperature associated with the start of the cooking cycle, i.e., approximately 50xc2x0 F. below the equilibrium start temperature, for example. Upon sensing the end of the cooking cycle at the dump point, the PLC initiates a dump cycle and controllably energizes the dump motors to tilt the kettle and dump the finished popcorn onto the surface platform. The popcorn is immediately and automatically dumped at the end of a proper cooking cycle, therefore preventing the popcorn from burning. Furthermore, because of the unique temperature-driven control of the popper, the popcorn is consistently and properly cooked and may be served at the peak of freshness. The greater the amount of corn and oil added, the longer the cooking cycle. Conversely, the less the amount of corn and oil, the shorter the cooking cycle.
Preferably, the motors are controlled to dump the kettle twice to ensure complete dumping. After the first dump, the kettle is only partially returned to a cooking or popping position. It is then dumped again before fully returning to a popping position.
When the temperature controller indicates that the kettle temperature is below the cooking cycle point and the machine is in a cooking cycle, the PLC disables the dump motors and thus prevents inadvertent dumping of the kettle contents.
When the popcorn has been dumped at the end of a cooking cycle, the kettle will heat back up to the start cook point again, and audible and visual indications are again initiated to remind a busy operator to reload the kettle with fresh ingredients. This prevents delays in between consecutive batches of popcorn and thus increases the efficiency of the operator and the popcorn popper, increasing production rates and profitability.
The present invention provides the proper application of heat energy consistently to batches of corn kernels. In that way, the kernels are heated to a sufficient temperature to provide proper hull brittleness and expansion when the kernels pop but the heat is not so high so as to force out the steam in the kernel prematurely. Therefore, the invention achieves the desired corn temperature and peak steam pressure for proper expansion. Expansion rates of approximately 1:50 have been achieved with the invention which is a significant improvement over some conventional devices which achieve expansion rates of 1:44 or lower.
Therefore, the present invention automates the cooking and dumping of popcorn and eliminates the need for constant operator attention to the process. Production of consistently popped corn is increased as is the profitability of the operation while incidents of burned corn and inadvertently spilled oil or uncooked corn are eliminated. Furthermore, the temperature control of the kettle operation and the cooking cycle provides properly and consistently cooked batches of popcorn.
The above and other objectives and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.